﻿<p>The element component type <b>IfcDiscreteAccessoryType</b> defines commonly shared information for occurrences of discrete accessorys. The set of shared information may include: <ul>
<li>common properties with shared property sets</li>
<li>common representations</li>
<li>common materials</li>
<li>common composition of elements</li>
</ul><p>It is used to define a discrete accessory type specification indicating the specific product information that is common to all occurrences of that product type. 
The <b>IfcDiscreteAccessoryType</b> may be declared within <em>IfcProject</em> or <em>IfcProjectLibrary</em> using <em>IfcRelDeclares</em> and may be exchanged with or without occurrences of the type. Occurrences of <b>IfcDiscreteAccessoryType</b> are represented by instances of <em>IfcDiscreteAccessory</em>.</p>

  <blockquote class="history">HISTORY&nbsp; New entity in IFC4.</blockquote>

<p class="use-head">Type Use Definition</p>
    <p>
      The exact type information of the
      <em>IfcDiscreteAccessoryType</em> is given in the
      <em>PredefinedType</em> attribute, possibly in combination with the
      <em>ElementType</em> attribute inherited from
      <em>IfcElementType</em>. Standard <em>ElementType</em> designations are
      provided for guideline below. The list is not exhaustive and
      the list of definitions may be extended based on local
      agreements.
    </p>
    <p>
      Corbels as separate components:
    </p>
    <ul>
      <li>
        <b>'Hidden steel corbel'</b>: Corbel system made from steel
        components embedded into the master element.
      </li>
      <li>
        <b>'Visible steel corbel'</b>: Corbel system made from
        steel components protruding from the master element.
      </li>
      <li>
        <b>'Visible concrete corbel'</b>: Corbel system made as a
        separate precast concrete component added to the master
        element.
      </li>
    </ul>
    <p>
      Connecting accessories, for example for sandwich wall panels:
    </p>
    <ul>
      <li>
        <b>'Diagonal truss connector'</b>: A fixing device in truss
        form with diagonal cross bars holding two precast conrete
        panels together in a sandwich wall panel.
      </li>
      <li>
        <b>'Ladder truss connector'</b>: A fixing device in truss
        form with straight cross bars in ladder form holding two
        precast conrete panels together in a sandwich wall panel.
      </li>
      <li>
        <b>'Panel suspender'</b>: A straight fixing device holding
        two precast conrete panels together in a sandwich wall
        panel.
      </li>
    </ul>
    <p>
      Electrical accessories for precast concrete elements:
    </p>
    <ul>
      <li>
        <b>'Protective plug'</b>: Protective plug used in element
        for protecting electrical accessories during manufacturing,
        transportation and assembly.
      </li>
    </ul>
    <p>
      Fixing parts:
    </p>
    <ul>
      <li>
        <b>'Standard fixing plate'</b>: Standard fixing plate.
      </li>
      <li>
        <b>'Edge fixing plate'</b>: Fixing plate attached to the
        edge of an element.
      </li>
      <li>
        <b>'Corner fixing plate'</b>: Fixing plate attached to the
        corner of an element.
      </li>
      <li>
        <b>'Slab fixing plate'</b>: Fixing plate for slabs.
      </li>
  <li>
    <b>'Channel fixing'</b>: Fixing channels, often realized as cast-in channels.
  </li>
  <li>
    <b>'Balcony hinge'</b>: Accessory supporting and fixing balconies.
  </li>
  <li>
    <b>'Frame shoe'</b>: Fixing shoe for frames.
  </li>
      <li>
        <b>'Thermo frame'</b>: Thermo frame.
      </li>
      <li>
        <b>'Column shoe'</b>: Fixing shoe for columns.
      </li>
      <li>
        <b>'Wall shoe'</b>: Fixing shoe for walls.
      </li>
      <li>
        <b>'Fixing socket'</b>: Fixing socket.
      </li>
    </ul>
    <p>
      Joint accessories:
    </p>
    <ul>
      <li>
        <b>'Neoprene bearing plate'</b>: Rubber plate used as a
        bearing in, for example, joints between column corbels and
        beams.
      </li>
      <li>
        <b>'Working joint reinforcement'</b>: Reinforcement
        accessory used in working joints.
      </li>
      <li>
        <b>'Expansion joint reinforcement'</b>: Reinforcement
        accessory used in expansion joints.
      </li>
      <li>
        <b>'Ribbed steel bar extension'</b>: Extension accessory
        made of a ribbed (reinforcement) bar used in joints.
      </li>
      <li>
        <b>'Steel pin bolt'</b>: Pin bolt used to join together,
        for example, columns and beams.
      </li>
      <li>
        <b>'Concrete dowel'</b>: Dowel pin used in joints.
      </li>
      <li>
        <b>'Concrete groove'</b>: A groove made in a joint.
      </li>
      <li>
        <b>'Steel plate'</b>: A steel plate used as an accessory in
        a joint.
      </li>
      <li>
        <b>'Wire loop'</b>: A joint connector accessory made from a
        wire loop.
      </li>
      <li>
        <b>'Steel loop'</b>: A joint connector accessory made from
        a steel bar loop.
      </li>
      <li>
        <b>'Sealing strip'</b>: A strip sealing the joint.
      </li>
      <li>
        <b>'Sealing compound'</b>: Sealing compound protecting and
        sealing the joint.
      </li>
    </ul>
    <p>
      Lifting accessories:
    </p>
    <ul>
      <li>
        <b>'Wire lifting hook'</b>: A lifting aid in the form of a
        wire loop.
      </li>
      <li>
        <b>'Steel lifting hook'</b>: A lifting aid in the form of a
        steel bar loop.
      </li>
      <li>
        <b>'Lifting socket'</b>: A lifting aid in the form of a
        socket.
      </li>
      <li>
        <b>'Steel lifting anchor'</b>: A lifting aid in the form of
        a steel lifting anchor.
      </li>
      <li>
        <b>'Lifting hole'</b>: A lifting aid in the form of a hole.
      </li>
    </ul>
    <p>
      Accessories mainly used in the building services domain:
    </p>
    <ul>
      <li>
        <b>'Antivibration'</b> : An isolating device to prevent
        other elements to be effected by vibrations.
      </li>
      <li>
        <b>'Drop rod'</b> : A length of material providing a
        hanging support to a bracket. Note that a drop rod is
        considered to include nuts and washers required for
        securing.
      </li>
      <li>
        <b>'Duct foot'</b> : A base support used to receive a
        vertical pipe .
      </li>
      <li>
        <b>'Framing'</b> : A frame placed around a penetration to
        prevent scraping against the building surface or structure.
      </li>
      <li>
        <b>'Grommet'</b> : An element placed within a penetration
        that seals the penetration for a particular reason.
      </li>
      <li>
        <b>'Rack'</b> : A set of shelving for the purposes of
        storage that may be freestanding or bolted to a structure.
      </li>
      <li>
        <b>'Safety part'</b> : A part, typically installed in
        vertical shafts at each level, to ensure safety from
        falling when entering the shaft.
      </li>
      <li>
        <b>'Sleeve'</b> : A thin barrier placed between a
        penetration and a penetrating element.
      </li>
      <li>
        <b>'Support section'</b> : A section of material that is
        used as an intermediate support upon which multiple
        brackets can be mounted.
      </li>
    </ul>



